Bidirectional coupling of electromagnetic and thermal processes in radiofrequency hyperthermia

Hyperthermia and coagulation therapies are based on the tissue heating and represent minimally invasive medical procedures; they are recommended for the treatment of tumors in soft tissues (liver, kidney, breast, etc.). The energy is delivered to the tissue through a microwave (MW) thin antenna, inserted transcutaneously. Both procedures require a careful preparation for the intervention; the power and frequency of the MW source, the design of the antenna, the time interval while the energy is delivered are some significant factors that determine the temperature distribution in the target tissue. Numerical modeling of the intervention is a research tool, useful for the optimization of the procedure. The coupled phenomena, electromagnetic and thermal, are analyzed here in a numerical experiment with the finite element method (FEM); electromagnetic field (EMF), absorbed power density and temperature distributions are computed inside the exposed volume of tissue and the energetic efficiency of the applicator is evaluated.